Axons can be myelinated (wrapped in a myelin sheath) – allowing for faster nerve impulse conduction – or non-myelinated (without a myelin sheath). In collaboration with the research group of Professor Carmen Birchmeier, developmental biologist at the MDC, Dr. Grigoryan showed in mice how axon myelination or non-myelination is regulated in the peripheral nervous system (PNAS, doi: /10.1073/pnas.1310490110)*.
Besides neurons, glial cells are also key players in the nervous system. “Without the support of the glial cells, the nerve cells would not be able to function,” said Dr. Grigoryan. In the peripheral nervous system the Schwann cells play an important role. These are a group of glial cells named after their discoverer Theodor Schwann (1810-1882). Schwann cells surround the axons and form a myelin sheath. “Following a nerve injury in the peripheral nervous system, the Schwann cells trigger axon regeneration.” However, not all axons have a myelin sheath. How is this process regulated?
“At the beginning of their development in the embryo, the axons are grouped in bundles as extension of a nerve cell and are surrounded by a Schwann cell,” said Dr. Grigoryan. “At birth, however, the Schwann cell begins to sort out the thick axons from the bundle and to wrap them in a myelin sheath. The thin axons are not sorted out – they remain bundled and do not receive a myelin sheath. Researchers call this process axonal radial sorting.”
The large and thicker axons are wrapped by the Schwann cells in multiple layers. Due to this myelin insulation – like a power cable sheathed in plastic – these axons, for example of motor neurons, can transfer information very fast. This is why you can pull your hand quickly away from a hot stove, because the axons signal the information “hot – danger of burns”.
This fundamental process is regulated by a signaling pathway which researchers in Professor Walter Birchmeier’s laboratory have been studying for many years – the Wnt/beta-catenin signaling pathway. It is one of the best-studied signaling pathways. It plays a key role in embryonic development, cell growth (proliferation), cell maturation or cell specialization (differentiation) and in the regulation of stem cells, and, as the most recent work from the MDC now shows, even in the formation and differentiation of axons.
The research team attaches special significance to its discovery, since a dysregulation of Schwann cells can lead to a number of serious diseases. Dr. Grigoryan and her colleagues hope that this discovery will not only contribute to a better understanding of Schwann cell development but also to deeper insight into the pathogenesis of diseases in which these cells are involved.
*Wnt/Rspondin/β-catenin signals control axonal sorting and lineage progression in Schwann cell development
Tamara Grigoryana, Simone Steina, Jingjing Qia, Hagen Wendeb, Alistair N. Garrattc, Klaus-Armin Naved, Carmen Birchmeierb, and Walter Birchmeiera,1
aCancer Research Program and bNeuroscience Program, Max Delbrück Center for Molecular Medicine, 13125 Berlin, Germany; cCenter for Anatomy, Charité University Hospital, 10117 Berlin, Germany; and dDepartment of Neurogenetics, Max Planck Institute for Experimental Medicine, 37075 Göttingen, GermanyContact:
Barbara Bachtler | Max-Delbrück-Centrum
New risk factors for anxiety disorders
24.02.2017 | Julius-Maximilians-Universität Würzburg
Stingless bees have their nests protected by soldiers
24.02.2017 | Johannes Gutenberg-Universität Mainz
In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport
Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...
The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.
The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...
Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...
Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".
Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...
13.02.2017 | Event News
10.02.2017 | Event News
09.02.2017 | Event News
24.02.2017 | Life Sciences
24.02.2017 | Life Sciences
24.02.2017 | Trade Fair News